The long-awaited housing recovery finally took hold in 2012, heralded by rising home prices and further rental market tightening. While still at historically low levels, housing construction also turned the corner, giving the economy a much-needed boost. But even as the most glaring problems recede, millions of homeowners are delinquent on their mortgages or owe more than their homes are worth. The number of households with severe housing cost burdens has set a new record.

These are some of the key findings from The State of the Nation’s Housing 2013, recently released by Harvard University’s Joint Center for Housing Studies. The turnaround in home prices has been widespread. As of the end of 2011, 81 of the 100 metropolitan areas tracked by CoreLogic still reported year-over-year price declines. Just one year later, prices were on the upswing in 87 of these markets. The momentum has continued into 2013, lifting the number of markets with rising prices to 94.

Multiple factors have bolstered house prices, including record low mortgage interest rates and steady, if not spectacular, employment growth. Low inventories of properties for sale are also a key driver, with supplies of both new and existing homes well below the six-month level that traditionally indicates a balanced market. Institutional as well as mom-and-pop investments in distressed single-family homes have also served to firm prices in certain markets.

Rising home equity provides owners a greater sense of security about spending, especially on big-ticket items such as home improvements. Even modest price appreciation over the next year should also put some of the 4 million households that have limited equity or are only slightly underwater in a better position to sell. This would, in turn, expand the supply of homes for sale.

The national homeownership rate fell for the eighth straight year in 2012, from 66.1 percent to 65.4 percent. This drop reflects not only the addition of 1.1 million renters, but also a net loss of 161,000 homeowners for the year. The rollback was especially pronounced among African-Americans, whose homeownership rate has now dropped 5.8 percentage points from the peak and is back to its lowest level since 1995. The decline among Hispanics was a more modest 3.3 percentage points. Their rate still exceeds 1990s levels.

How much farther homeownership rates will fall is an open question. The overall homeownership rate is only as high as it is because households over age 65 now have the highest rates on record and account for an ever-larger share of the population.

With the addition of 1.1 million renter households last year, much of the increase in rental demand has been met by conversion of single-family homes to rentals. Between 2007 and 2011, on net 2.4 million homes switched from owner-occupied to renter-occupied — several times more than the 900,000 rental units started during this period. Tenure switching has been an important safety valve for the single-family market, absorbing the excess owner-occupied housing.

The number of households with housing cost burdens continues its inexorable climb. At last count in 2011, more than 40 million households were at least moderately cost burdened (paying more than 30 percent of their incomes for housing), including 20.6 million households that were severely burdened (paying more than half of their incomes for housing). Copies of The State of the Nation’s Housing 2013 are available for download at www.jchs.harvard.edu.

Kermit Baker is the senior research fellow for the Joint Center of Housing Studies at Harvard University. He may be reached via e-mail at kermit_baker@harvard.edu.